Sunshine and warmer weather are accelerating crop and weed growth. Because of varied planting and replanting dates, both corn and soy post herbicide applications are underway. Largest corn is V9 – V10 stage, soy is V4 to V5 and nearly R1 (beginning bloom, one open flower at any node on the main stem). We are getting flowers on soy over a week before summer solstice! Despite what some of us learned about the connection between the longest day of the year and flowering, this phenomenon is becoming more frequent with earlier plantings. Photoperiod sensitive soybeans are considered a short-day plant. Despite the inference, flower induction is triggered with a longer night length. The soy plant’s ability to measure night length starts early, when the unifoliate leaflets are present and a young trifoliate can be detected at the second node. Dependent upon the soybean variety and maturity, once that plants critical night length is reached, flowering is initiated, before or after June 21st.
With our Dicamba products for Xtend technology soy reaching their June 12th application cutoff in Illinois, we should also look at label recommendations for Enlist products. The Enlist One label specifies for post applications applied to Enlist traited soy, ” Apply when weeds are no larger than 6 inches and any time after soybean emergence through the R1 growth stage.” As always, take the time to read and follow label directions before mixing and applying pesticides.

A good growing week in NE Illinois for most. Some precipitation and several rain free days with sunshine. The earliest planted corn is V7 to V8 and earlier planted soybean is V3 to V4. Now that most planters are parked, other activities are underway. They include sidedressing nitrogen, post herbicide applications on corn, and harvesting the first cutting of hay. Several days after corn post herbicide applications have taken place, scout fields to evaluate the performance of your post herbicide application. Be wary of hard to control weeds such as Marestail, with populations resistant to glyphosate in Illinois and a challenge to other chemistries once they bolt and reach a height of 6 – 8 inches. To learn about the newest in weed management plan on attending the University of Illinois 2024 Weed Science Field Research Tour on June 26th. The tour takes place at the Department of Crop Sciences field research location known as the Clem Farm, located at 1114 County Road 1200 East, Champaign. Registration begins at 8:00 a.m. and the tour will start at 9:00 a.m.

A dryer weather pattern allowed most to finish or nearly finish planting or replanting. Earliest planted corn is near or at V6 and earlier planted soy is now V3. We encourage early scouting of fields, including replant areas to evaluate crop emergence (note soy replant seedling feeding in picture), weed pressure and height. Expecting post corn herbicide applications to start soon.

Drying out this week in Northeast Illinois, planters are rolling, in instances planting fields for the first time, and replanting in others. Fields that held ponded water are noticeably uneven in emergence and early season growth. As the growing season progresses it will be interesting to follow the development in these fields. Earlier planted corn has reached V4 to V5, most soy I scouted are somewhere between just planted and V1, one fully developed trifoliolate. I plan on visiting an early planted soy field later this week and will be interested in its stage of development. Again, I posted another Waterhemp image this week demonstrating the rapid growth of weeds with improving growing conditions.

In Northeast Illinois some were fortunate to plant for several days while others have yet to attempt field work in the month of May. Crop scouting is critical to determine stand counts and the presence of drowned out areas. Waterhemp seedlings can easily be found in fields. For post herbicide applications be aware of weed height recommendations. A general rule is treating most weeds in the 3 to 4 inch stage.

The start of another growing season! Limited field activity for nearly two weeks, our most recent precipitation event on May 7th will continue this trend. Planted corn is reaching V1 and planted soybean emerging, but plenty of seed can still be found in bags. Unworked or sprayed fields are full of winter annuals including Butterweed. Reports of significant alfalfa leaf feeding in regional hay fields. In the two most recent growing seasons farmers harvested almost 100% of planted acres with few drowned out areas, that is not likely in this region in 2024.

Corn is at R5 (dent) and most soy is at R6 (full seed), fields that still have green tissue are benefitting from recent rainfall. Areas that experienced drought conditions after pollination and during grain fill can expect corn kernel abortion near the ear tip and smaller and lighter kernels. This would be a good year to check stalk strength among hybrids and plan field harvest order accordingly. Some encouragement to hand-pull surviving Waterhemp in fields before they produce viable seed. Last week at the Farm Progress Show Dr. Aaron Hager’s team demonstrated Waterhemp samples collected from populations that were resistant to six herbicide modes of action. This includes Group 4, the growth regulators which include 2,4-D and dicamba. It has been an uneventful insect pest year to date; however, Soybean aphids were recently collected in Northeast Illinois by the Suction Trap Network https://suctiontrapnetwork.org/ and Stink bugs are easily found in soy fields I have visited.

Recent high day and nighttime temperatures have local farmers and crops stressed. In my immediate area in Northeast Illinois the opportunity for “Bonus fill” of kernels experienced last year appears very unlikely as the R6 (dent) corn hastens to maturity. Fields with greater water holding capacity are faring much better than lighter soils, but even those are showing some remobilization of nutrients from lower leaves in the canopy for the ear. Soy are nearing R6, having a green seed filling the pod at one of the top 4 nodes on the main stem with an open trifoliate.

Again, sounding like a broken record, hit or miss on rainfall for areas in NE Illinois. This past week some fields received inches while others received tenths. While management decisions are dwindling this late in the growing season, we can still learn from field visits. An area in a soybean field that from the road I predicted to be SDS or BSR turned out to be White Mold. While scouting I’m also noting vines becoming more visible, most on field edges, predominantly morningglories, but also Burcucumber. The morningglories can be frustrating during harvest, but Burcucumber can wrap on the reel and bring harvest to a stop. If you find areas with significant amounts of Burcucumber you may consider a harvest aid treatment. We are almost R5 for both crops, near dent stage in our corn and at or near beginning seed in our soybean. Continued low insect and disease pressure in fields I have visited.

Hit or miss on rainfall for areas in NE Illinois this past week. Enough precipitation to keep the crops going, but few if any tile lines are running. Overall disease pressure continues to be low in both corn and soy fields I have visited, including those that did not receive a fungicide treatment. To date, very low insect pressure has been found in either crop. Not surprising, I’m noting Common Smut on corn field edges damaged by deer feeding. Most of the area corn crop is currently at R4 or the dough stage. The starch in the kernel, initially a liquid, is converting to a more solid or pasty consistency. Cool sunny days are favorable for an extended R4 stage. Much of the Sb crop is at R4 or full pod.